The present invention is concerned with mechanism in a machine for sealing tops and bottoms of cartons including their infolded side and end flaps, after they have been loaded with contents for delivery, such sealing being selected from a variety of types of carton closures, e.g., stapling, gluing and applied adhesive tapes, preferably the latter, so as securely to anchor the folded top and bottom flaps. More specifically, the present invention is directed to a relatively simple but unusual solution of permitting an operator to set up a folded carton blank into an empty carton with its top flaps extending upward in open positions and with its bottom flaps infolded and firmly held down upon a loading support so that the operator may easily load the intended contents in the carton empty chamber, to be followed by a folding down of the top flaps to carton-closing positions and releasing the carton for transport through the machine so as to effect anchorage of the folded top and bottom flaps. Accordingly, it is preferred that such a machine include a lateral base structure and an elevator head structure with the latter supported on suitable vertical support structure for slidable up-and-down movement. Such a type of carton sealing machine is disclosed in the copending Warshaw et al. U.S. Patent application Ser. No. 645,718 of Dec. 31, 1975 and Loveland et al. U.S. patent application Ser. No. 648,916 of Jan. 14, 1976, and the disclosures thereof are embodied herein by reference.
It is a general object of the present invention efficiently to embody in such a machine and its operating mechanisms relatively economical equipment which will demand minimum attention from the operator while the latter is engaged in loading the intended content of each carton into its empty chamber as the machine securely holds such carton automatically in a helpful upright position at a location where it is ready to be released immediately to the transporting equipment of the machine for progressive sealing of the carton top and bottom folded flaps.
Another object of the present invention is to employ in a unique and efficient manner side guide rails structure of such a machine for temporarily holding such carton in a proper upright position during the loading procedure while then after a simple command from the operator will serve as the usual pair of side guides for the transport movement of the loaded carton through the machine and past its sealing means applying equipment.
A more specific object of the present invention is to provide such side guide rails with elongated entrance ends which will lap along opposite sides of an open top carton that is being rested upon a lateral loading surface or table top and causing such side rails to move inward for snugging these elongated entrance ends against opposite sides of the carton for securely holding it in its desired upright position, whereby with such carton being located between the rail entrance ends it will automatically be in proper position for immediate forward movement between the guide rails through the machine.
A still further object of the present invention is to program the operating mechanisms of the machine whereby the inward movement of the side rails to their carton-clamping positions is effected prior to activation of the elevator head for raising it any appreciable amount above its initial lower position, so that this head is at the ideal location for start of processing of the loaded and clamped carton through the machine to subject it to the action of the sealing equipment.
In accordance with the present invention the sealing machine equipment is provided with motive power means to move the side clamping and guiding rails one toward the other for closer approach and alternately reversely outwardly away from the other for wide separation, with the elevating head being associated with motive power means to lift and lower it at will while locating it at a lower elevation upon energization of the machine mechanism. Control means on the approach end of the elevator head provides for engagement by a carton transported forward between the entrance ends of the guidance rails into the entrance end of the machine bed from a position on loading lateral support means preceding the machine entrance, such as a loading table top. This control means on the approach end of the head is of a character that when manipulated by a forwardly transported carton engaging thereagainst will lift the head above the elevation of the closed top of the advancing carton so that the latter may be advanced immediately below the head with the latter loading the folded top flaps constituting the temporary top closure of the carton until securement by sealing means which is to be applied thereto in the transport of the carton to the machine discharge end. The motive power means which manipulate the side rails and also the elevating head effect these functions in certain timed relation so that the side rails are moved inwardly for closer approach to snug a carton therebetween before lift is applied to the elevator head. For this purpose an energy operational and controlling circuitry is provided which includes the side rails and head motive power means and a suitable energy source to effect operational functionings thereof in an efficient manner. The equipment in such circuitry may be of a nature to be operated or driven by any one or more of suitable types of energy, e.g., electrical and/or pressurized gaseous medium, such as pneumatic equipment. It may be preferred that the rail driving and head elevating means, such as motors, be pneumatic cylinder motors with each separately connected to a common source of pressurized air through a separate one of a pair of control valves with each having a pressurized air manipulated valve member. Such control means on the approach end of the lowered elevator head may be provided with means dividing its pressurized air delivery for flow separately to one of the control valves with the divided flow to the driving rail control valve manipulating member being direct. In contrast to such direct flow to the manipulating member of the control valve for the driving rail action intermediate control valve means which intervene the lowered head control means and the head elevating control valve manipulating member imposes a greater time lag upon the initiation of the lifting of the head, whereby the earlier action of the inward motion of the side rails accomplishes the desired clamping of the empty carton in its loading position with an upright attitude most favorable to the loading operation prior to the ultimate desirable lift movement of the head and at a time when the loaded carton has had its top flaps folded inward into stacked relation for a flat top closure that will now allow the carton properly to be processed through the machine and past its sealing mechanisms.